The present invention relates to ice making machines, and particularly to ice making machines that make flaked ice using an auger in a freezing cylinder.
Flaked ice is popular because flaked ice has a large surface area, and may be used to quickly cool a variety of items, including beverages, foods, injuries to people, and so on. Flaked ice may be made by size reduction of larger-sized ice cubes or particles, or in machines specially designed for making flaked ice. Such machines generally consist of a cylindrical chamber into which water is admitted, with a screw-type auger rotating in the center of the chamber. Cooling coils are generally attached to the outside surface of the cylinder, the cooling coils being the cooling portion of a refrigeration system used in the flaked ice-making machine.
Water is admitted to the bottom of the cylinder, and the auger is rotated slowly. Heat is removed from the water in contact with the cylindrical walls, which are in turn in contact with the cooling coils. As the water is progressively chilled, it freezes into ice. The ice is then shuttled out of the freezing cylinder and into a storage bin or holding unit for use. Water coming into the cylinder is usually held between certain levels in a water tank or reservoir, requiring replenishment when the water level is low, and the water supply must be shut off when the water level reaches a certain level.
Present flaked ice making machines are in need of improvement in several ways. When water is progressively frozen, the portion of the water that freezes tends to be more pure than the portion that remains. Thus, the auger and the cylinder tend to build up levels of impurities or minerals left behind when water freezes. Ice levels in the holding bin are difficult to measure. Present methods may involve intrusive sensors or paddles to detect ice levels. These sensors are unreliable and tend to block the flow of ice to the bin. The high-level and low-level sensors usually used to determine water level in the water tank tend to be unreliable. Finally, the compressor in the refrigeration system tends to cycle on and off rather than shut off completely in a bin-full condition, when there is no further demand for making ice. This condition should be avoided.
A flaked ice machine that could be easily cleaned of the mineral deposits would be an improvement over presently-available machines. A flaked ice machine that had an ice level sensor that does not interfere with the production or transport of ice would also be desirable. It would also be an improvement to have a flaked ice machine whose control system could sense when more ice is not needed and would turn off the compressor.
An improved ice making machine has been invented which is easily cleaned, has an ice level sensor that does not interfere with ice production, and has a control system which shuts down the compressor when the bin is full. An improved machine for making flaked ice has a water system, a refrigeration system, and a microprocessor-based controller. The water system comprises at least one water inlet, a level control inlet valve and an independently operated inlet valve operably connected to the inlet, the valves in series with the inlet, a reservoir for receiving water from the inlet and the valves, the reservoir also containing at least one water outlet. The water system also comprises a freezing cylinder communicating with the water reservoir, the freezing cylinder further comprising an auger having a screw edge and a motor for rotating the auger, and a discharge valve. The refrigeration system comprises a compressor, a condenser, an expansion device and cooling coils in heat transfer relationship with the freezing cylinder for receiving coolant from the expansion device to cool water from the water system. The microprocessor-based controller controls the independently operated inlet valve.
Another aspect of the invention is a method of operating a flaked ice making machine. The method comprises the steps of adding water to a reservoir through a solenoid inlet valve in series with a float valve. The method includes transferring water from the reservoir to a cylinder containing an auger. The auger is rotated and heat is exchanged between the water and the environment, causing the water to freeze. The method then includes removing ice formed by said freezing from said cylinder.
Another aspect of the invention is a flaked ice making machine comprising a water reservoir, a water inlet, a freezing cylinder, an ice chute and a controller. The water reservoir further comprises a water level sensor, a water outlet, and a discharge valve. The water inlet further comprises an inlet float valve and a solenoid inlet valve, operably connected in series to fill the water reservoir. The freezing cylinder is operably connected to receive water from the outlet of the water reservoir, and the freezing cylinder further comprises an auger having a screw edge therein and a motor to rotate said auger, and the freezing cylinder also comprises cooling coils on the outside thereof connected to a compressor and a condenser for exchanging heat to freeze water inside the cylinder. The ice chute is for receiving ice from said freezing cylinder and further comprises an ice chute sensor within the ice chute. The controller is operative to control making of flaked ice by closing the solenoid valve and turning off the motor and the compressor upon receiving a signal from the ice chute sensor.
Another aspect of the invention is a flaked ice making machine. The flaked ice making machine comprises a water reservoir, including a water level sensor, a water outlet and a discharge valve, and also comprises a water inlet valve operably connected to fill the water reservoir. The ice machine further comprises a freezing cylinder operably connected to receive water from the outlet of the water reservoir, the freezing cylinder further comprising an auger having a screw edge therein and a motor to rotate said auger, and cooling coils on the outside thereof connected to a compressor and a condenser for exchanging heat to freeze water inside the cylinder. The flaked ice making machine also comprises an ice chute communicating with the freezing cylinder for receiving ice from the freezing cylinder, the ice chute further comprising a capacitive sensor for determining an ice level within said chute. The machine also comprises a controller, wherein the controller is operative to control making of flaked ice by opening and closing the water inlet valve and the discharge valve, and by turning on and off the motor and the compressor.
Another aspect of the invention is a method of operating a flaked ice making machine having a capacitive ice bin sensor. The method comprises adding water to a reservoir though an inlet valve, and transferring water from the reservoir to a cylinder containing an auger. The method then includes rotating the auger, and exchanging heat between the water and an environment, wherein the water freezes. The method also includes removing ice formed by said freezing from said cylinder and ceasing to make ice upon a signal from a controller or a power interrupt.
The advantages of the machine for making flaked ice include a more reliable water inlet system, using both a level control valve and an independently-controlled valve. This dual-valve system also makes it much easier to run a cleaning cycle as needed or as desired, without the need for manual control of the valves for rinse water. A special non-intrusive sensor in the ice-bin may give a reliable signal or indication of a bin-full condition, enabling the controller to shut down the refrigeration equipment, rather than running the refrigeration equipment when it is not needed. These and other aspects and advantages of the invention will be made clearer in the accompanying drawings and explanations of the preferred embodiments.